Decorative films, such as simulated wood films, are used for providing a pattern, such as the appearance of real wood grain, to many surfaces including furniture, countertops, walls, siding and the like.
U.S. Pat. Nos. 3,666,516, 3,770,479 and 3,953,635 by Dunning teach heat-stamped simulated wood-grain films. Further such simulated films may be found in U.S. Pat. No. 5,503,905 of Gregory Boris. Many such films are useful on flat or generally flat surfaces to provide an outer-layer laminate which has the look and appearance of real wood or to provide a decorative pattern to a substrate such as fiberboard, particle board and the like.
Most films of this nature are formed of two general constructions. The film may be formed from the bottom layer, intended for adhesion to the substrate surface, up to the top layer. An adhesive layer may be formed on a easily removable backing support sheet, followed by a base coat, design layers and a protective top layer and/or carrier sheet. In such a construction, the film is applied to the substrate by removing the backing support sheet and applying heat and/or pressure to the upper surface of the film, typically on the carrier sheet, to activate the adhesive and adhere it to the substrate surface. The carrier sheet is then removed from the film. Alternatively, as described in U.S. Pat. No. 5,503,905, such a film may be formed in the reverse order, i.e., from the top layer of the film down to the base, by applying the protective layer, top coat, design layers, base coat and adhesive layer to the carrier film. Such films are applied by contacting the adhesive layer with the substrate surface and applying heat and/or pressure to the film to activate the adhesive and adhere the film to the substrate. The carrier is then removed from the upper surface of the film. The carriers used in prior art decorative films are typically formed of polyester, polyolefin or cellophane and are intended to be easily removed from the decorative layers, in some instances, with use of an additional release layer between the carrier and the top of the decorative layers.
While many films are available for use on generally flat surfaces, these decorative films are difficult to apply, and do not always adhere well, maintain their structural integrity or form a smooth and defect-free appearance when used on three-dimensional surfaces, e.g., on wood trim having a routed carving or on the edges of tables having carved designs. Further, prior art films are typically not thermally stable and tend to shrink during processing. They are also not generally very durable.
Some heat molding films have been developed for providing a color coating to three-dimensional automotive body parts such as thermoplastic automobile panels and bumpers in the form of a laminate, as in U.S. Pat. No. 4,948,654 of Brooks. This patent teaches a polyetherester or copolyester carrier sheet which is coextruded or otherwise molded to an curved article such as an automobile bumper. The film is positioned in the mold for the article and a molten fluid capable of hardening into the shape of the article and to the film is injected in the mold.
U.S. Pat. No. 5,413,840 includes a laminated film for decorating medium-density fiberboard which has a polyvinyl chloride base film laminated by adhesive layer to a polyester film which is further laminated to a hard coat and protective layer. The film is formed to allow V-cut processing to form a notch for bending the film around a corner of a piece of fiberboard.
While the prior art films may be suitable for use on corners or in molding applications, there is a need in the art for a film which can be easily and smoothly adhered to a three-dimensional article without surface defects and which is also scratch resistant and durable. There is further a need in the art for a thermally stable film which does not exhibit significant shrinkage during processing.
The invention includes a decorative wrapping film for application to a three-dimensional substrate, comprising a biaxially-oriented polyester layer having a first surface for adhering to a three-dimensional substrate and a second surface; a decorative layer coated on the second surface of the polyester layer; and a protective layer coated on the decorative layer.
In one embodiment, the invention includes decorative wrapping film for application to a three-dimensional substrate, comprising a biaxially-oriented polyester layer having a first surface for adhering to a three-dimensional substrate and a second surface, wherein the biaxially-oriented polyester comprises a polyalkylene terephthalate selected from the group consisting of a polybutylene terephthalate and a polyethylene terephthalate and the polyester layer has a thickness of from about 50 to about 700 gauge (about 13 to about 178 microns); and a decorative layer coated on the second surface of the polyester layer.
The invention also includes a method for making a three-dimensional wrapping film, which comprises coating a first surface of a biaxially-oriented polyester layer with a decorative layer, wherein a second surface of the polyester layer opposite the surface coated with the decorative layer is capable of being applied to a three-dimensional substrate.
In one embodiment, the invention includes a method for coating a three-dimensional substrate, the method comprising adhering a decorative film at least partially around a three-dimensional substrate using an adhesive, wherein the film comprises a biaxially-oriented polyester layer having a first surface for adhering with the adhesive to the substrate and a second surface, and a decorative layer coated on the second surface of the polyester layer.